The present invention relates to an oil separator for an evaporator, and more particularly, to an oil separator for separating oil from refrigerant.
In such a product as a refrigerator or an air conditioner employing cool air, a cooling cycle including the processes of compressing, condensing and evaporating refrigerant is performed to generate the cool air.
Referring to FIGS. 4 and 5, a cool air generating system typically includes a compressor 51, a condenser 53, a capillary tube 55 and an evaporator 57. The compressor 51 compresses a gaseous refrigerant to a high-temperature and high-pressure gas and the condenser 53 condenses the high-temperature and high-pressure gaseous refrigerant to a high-pressure liquid. The liquefied high-pressure refrigerant is depressurized while passing through the capillary tube 55 and the depressurized refrigerant flows into the evaporator 57 and is then vaporized. While being vaporized, the refrigerant absorbs heat from air around the evaporator 57 to generate cool air. The thus-generated cool air is supplied to a cold storage and a freezing compartment of a refrigerator or inside a room. The vaporized refrigerant returns to the compressor 51 from the evaporator 57 to be compressed into the high-temperature and high-pressure gas.
In such a cooling system, since the compressor 51 compresses the refrigerant by a mechanical operation thereof, lubricating oil for mechanical parts of the compressor is needed. The lubricating oil is inevitably mixed into the refrigerant during the cooling cycle, and the refrigerant containing the oil circulates through the cooling system. When the liquid refrigerant containing the lubricating oil flows into the evaporator 57 to be vaporized, the lubricating oil maintains the liquid state and is separated from the vaporized refrigerant in a separator 58. Thus, the lubricating oil remains and accumulates inside the evaporator 57. This phenomenon is severe in the case that an ester oil is mixed into an HFC-134a refrigerant. Especially, when a mineral oil which is mainly used at the time of assembling the compressor 51 is mixed with the ester oil in the evaporator, separation of the mixed oil from the refrigerant during the vaporization in the evaporator 7 is significantly remarkable, to thereby increase the accumulation of the oil inside the evaporator 57.
The accumulation of the oil inside the evaporator obstructs a sufficient heat absorption from air around the evaporator, thereby decreasing a cooling efficiency. Accordingly, the amount of the lubricating oil inside the compressor becomes decreased resulting in abrasion of internal parts of the compressor, thereby decreasing a compressing efficiency and affecting the entire operation of the cooling system.